Cochlear implants have been a major advent in the field of hearing repair. Cochlear implants have aided patients suffering from severe hearing loss due to damaged neuroepithelial cells of the inner ear. Typically, during cochlear implant surgery, a cochlear implant is placed under the skin in a small dimple carved in the mastoid bone. The implant comprises a receiver and a delicate, highly flexible beam called an electrode array that is inserted into the cochlea. The receiver receives (e.g., from an external microphone with a processor and a transmitter) and delivers the necessary excitation to the auditory nerve via the electrode array. In this way, the electrode array restores some sense of hearing by bypassing damaged neuroepithelial cells (hair cells) in the inner ear and directly providing electrical stimulation to the auditory nerve.
During insertion, the electrode array is usually inserted into the cochlea through a round window into the scala tympani channel. This surgery involves a high level of risk because injuring the basilar membrane can result in complete loss of residual hearing.
The success and applicability of cochlear implants are currently limited by several factors. For example, during cochlear implantation, electrode array insertion is performed “blindly,” without controlling the interaction of the electrode array and cochlear duct. Also, for example, during implantation, the electrode array can buckle (e.g., from impacting the inner ear) and be rendered nonfunctional. Because of the risk, this surgery is typically performed on a limited subset of the population.